"...[O]ver 98% of the Fortune 500 and over 92% of the Global 500 [are] using iOS devices in their business today," Cook said in a statement introducing his company's enterprise mobility partnership with IBM last month.

But businesses also are using competing mobile devices, running Android, Windows Phone, or BlackBerry -- or all three -- often alongside iOS devices. Just because 98% of Fortune 500 companies use iOS doesn't mean that Apple's iOS accounts for 98% of the mobile enterprise market.

It appears that Apple's hold on the enterprise mobile market is slipping, although the company remains far ahead of the competition and its deal with IBM looks likely to fortify, if not improve, its position.

According to Good Technology, Android device activations among its 5,000 worldwide enterprise clients during the second quarter of 2014 reached 32% of total activations, an increase of five percentage points. Activations during this period for iOS devices, meanwhile, declined five percentage points to 67% of total activations. That leaves 1% for Windows Phone, which has remained flat for the past five quarters. BlackBerry activations are not tracked by Good Technology.

Android also is advancing in number of app activations, though it clearly has far to go. Android apps accounted for 12% of total app activations, a gain of four percentage points that comes from iOS app activations, which dropped from 92% in the first quarter of 2014 to 88% in the second quarter.

Assuming there's some lag between activating a device and actually using it for corporate work, app activations appear to reflect current device usage while device activations appear to indicate potential future device usage.

The good news for Apple is that its iPad remains the enterprise favorite, accounting for 90% of tablet activations. Android tablets represented 10% of activations, consistent with the third quarter of 2013 but down from 16% in the second quarter of 2013.

But Android phones are finding more fans among enterprise customers. They represented 30% of enterprise device activations, an increase of four percentage points. Apple's iPhone remained flat at 51% of all enterprise device activations.

Apple's leadership in the enterprise mobility market looks like it will continue for years, but Android is making slow, steady progress. It's Microsoft that should be most concerned about Good Technology's findings. To survive in the mobile enterprise market, Microsoft has to start winning more than 1% of enterprise mobile device activations.

Thomas Claburn has been writing about business and technology since 1996, for publications such as New Architect, PC Computing, InformationWeek, Salon, Wired, and Ziff Davis Smart Business. Before that, he worked in film and television, having earned a not particularly useful ... View Full Bio

"It appears that Apple's hold on the enterprise mobile market is slipping, although the company remains far ahead of the competition and its deal with IBM looks likely to fortify, if not improve, its position."

Thomas, you may be right, it seems that Apple is losing its grip over enterprise mobile markets. I think the main reason is that not too much innovation is happening at Apple labs after Steve Job's days. Now a day's peoples at enterprise level start using more Android based solutions

It isn't surprising to me given Apple had first mover advantage, and better security model. However, it is interesting to compare to market share. comScore April 2014 survey indicates Apple is the top OEM at 41%, with Samsung at 27.7%/ On the other hand, for smartphone platforms, Android is 52.5% with Apple at 41.4% (BB is 2.5% and decreasing quarter over quarter for more than a year). This implies BYOB style policy will continue to driveup Android as a percentage. The question is whether Android exceeds the market share percentage in the enterprise or does enterprise model the general market?

It's less surprising when you consider that Apple has traditionally pursued profitability rather than marketshare. At least since Jobs returned to the company in the late '90s, Apple has sought to make high-end products with good margins, even if that means a minority market share. It sees itself as a premium brand like BMW or Tesla rather than General Motors. Due to Microsoft's absence from the mobile market in the years since the iPhone changed everything in 2007, Apple also became the mass market leader, until Android matured. Now things are returning to the old paradigm, but with Android in place of Windows.

I'm surprised Android tablets haven't made more inroads in the enterprise. That's an area where the IBM-Apple partnership could be very interesting, as companies use tablets for large-scale laptop replacement, such as for sales teams or field repair/technicians.

Among 688 respondents, 46% have deployed mobile apps, with an additional 24% planning to in the next year. Soon all apps will look like mobile apps – and it's past time for those with no plans to get cracking.